This is a Program Project application for a Specialized Center of Research in Osteoporosis to be established at Creighton University manned by 4 experienced investigators. The theme of the Center is research into the etiology, prevention and treatment of osteoporosis. The 7 projects in this proposal will join 9 other current or pending projects. The projects are; 1) Family Studies in Osteoporosis, which will characterize the inheritance of osteoporosis, something which has not previously been accomplished. 2) Bone Histomorphometry Before and After Menopause which, will characterize the changes in bone cell function that underlie the rapid loss of bone occurring in humans immediately after menopause. 3) Nutrition and Bone Loss after Ovariectomy which will be a study of the ovariectomized rat as a model of trabecular bone loss, and the influence of dietary manipulations on that loss. 4) Identification and Treatment of Calcium Deficiency which will attempt to find a method of identifying dietary calcium deficiency in otherwise healthy women, and test whether giving calcium to these persons will inhibit bone loss. 5) Calcium Bioavailability from Certain Plant Sources, which will determine the extent to which oxalate and phytate interfere with calcium absorption, and assess calcium absorbability from several plant foods. 6) Restoration of Bone Mass by "Coherence" Treatment, which will be a trial of a method of restoring lost bone by activating remodeling sites, suppressing their resorptive activity, and then allowing bone formation to overfill the shallow resorption cavities, creating new trabecular bone. 7) Effect of a Strength Training Program on Bone Density, which will be a test of whether strength training of the muscles of the spine and hip will increase bone mass at these sites. These projects will advance the understanding of osteoporosis, and will bring us closer to reducing the morbidity and mortality associated with this condition which afflicts nearly half of our elderly population.